Production of nitric oxide and expression of class 1 hemoglobin gene of Lotus japonicus against rhizobial components

Abstract

In Lotus japonicus, inoculation of M. loti induced transient nitric oxide (NO) production in roots accompanying with the expression of LjHb1 (class 1 Hb of L. japonicus). When nodAC deficient mutant was inoculated, transient NO production was induced in roots, whereas LjHb1 was not induced. Inoculation of exo mutants induced neither NO production nor the expression of LjHb1. Inoculation of pathogen induced continuous NO production in roots. We had shown that application of crude lipopolysaccharide (LPS) of M. loti induced NO production and the expression of LjHb1. When purified LPS of M. loti were applied, NO production was induced in the roots. We focused on NO production and expression of LjHb1in L. japonicus and the rhizobial components that induce NO production and LjHb1 expression in host plant root will be discussed.